Thermal interruption capability of carbon dioxide in a puffer-type circuit breaker utilizing polymer ablation

When adopting an alternative arc quenching gas to SF₆ which has recently been recognized as a greenhouse gas, it is easily anticipated that the thermal interruption capability of the GCB will be lower than that in using SF₆. In this paper, adopting CO₂ as an alternative gas, the means utilizing ablation phenomenon of polymer materials as one of the breakthrough technologies compensating the drop in the interruption performance will be proposed and tested by a full-scaled GCB model. As a result, a change in the blasting pressure characteristics was observed, and also the peak pressure for the ablation application model was about 1.3 times higher than that of the conventional model without the ablation element. Furthermore, even if compared at the same blasting pressure condition at current zero, the thermal interruption capability of the CO₂ gas in the ablation application model was presumed to be improved with comparison to the conventional model without the ablation element. The thermal interruption capability of the CO₂ gas in the ablation application model could be estimated to be about 50 % of that of SF₆ gas in the conventional model in this interrupting test.